Preparation of several acyclonucleosides containing both a difluoromethylphosphonate group and a triazole moiety is described starting from a difluorophosphonosulfide. The key step of the synthesis involves a copper(I)-catalyzed Huisgen 1-3 dipolar cycloaddition between difluorophosphonylated azides and propargylated nucleobases derived from thymine and 2-amino-6-chloropurine.

The relaxation of nuclear dipolar energy to the lattice has been measured in three different organic solids (benzene, cyclohexane and hexamethylbenzene) as a function of temperature. In the cases of C6H8 and C 6 (CH 3 ) 6 very slow motions associated with rather high activation energy were detected near the melting point. They are thought to be thermally activated rotations of the molecules abo...

Investigations were made of rotary resonance recouplings (R) of chemical shift anisotropy ~CSA!, heteronuclear dipolar ~HTD!, and homonuclear dipolar ~HMD! couplings involving half-integer quadrupolar nuclei under magic-angle sample spinning condition. Under rotary resonance conditions provided by a low amplitude rf field and a high spinning speed, the spectrum of the central transition coheren...

We calculate perturbatively the effect of a dipolar interaction upon the Bose-Einstein condensation temperature. This dipolar shift depends on the angle between the symmetry axes of the trap and the aligned atomic dipole moments, and is extremal for parallel or orthogonal orientations, respectively. The difference of both critical temperatures exhibits most clearly the dipole-dipole interaction...

It has previously been shown that the dipolar field effect spatially localizes photochemical reaction products on the surfaces of macroscopic ferroelectric crystals. In this work, photochemical reactions that deposit insoluble products on the surface have been used to study the dipolar field effect in microcrystals of BaTiO3 and Sr2Nb2O7. In both cases, the patterns of reduced silver on the sur...

The dipolar method associated with a nonlinear time domain simulation program make up a powerful tool to analyze high Q-factor circuits like quartz crystal oscillators. After a brief remainder of the dipolar method, the paper will attempt to identify the main amplifier characteristics such as limitation mechanism, input and output impedances, etc. and to point out their influence on the amplifi...

The symmetry properties of the Cooper pairing problem for multicomponent ultracold dipolar molecular systems are investigated. The dipolar anisotropy provides a natural and robust mechanism for both triplet and singlet Cooper pairing to first order in the interaction strength. With a purely dipolar interaction, the triplet pz-like polar pairing is the most dominant. A short-range attractive int...

.........................................................................................23 Introduction....................................................................................24 Theory............................................................................................25 Results and Discussion...................................................................32 Conclusions ....

Phosphonated isoxazolinyl nucleosides have been prepared via 1,3-dipolar cycloaddition reaction of nitrile oxides with corresponding vinyl or allyl nucleobases for antiviral studies. The cytotoxicity, the anti-HSV activity and the RT-inhibitory activity of the obtained compounds were evaluated and compared with those of AZT and diethyl{(1'SR,4'RS)-1'-[[(5-methyl-2,4-dioxo-3,4-dihydropyrimidin-1...

A series of spiro[isoindole-1,5-isoxazolidin]-3(2H)-ones has been synthesized by 1,3-dipolar cycloaddition of N-benzylnitrone with isoindolin-3-methylene-1-ones. The regio- and stereoselectivity of the process have been rationalized by computational methods. The obtained compounds show cytotoxic properties and antiproliferative activity in the range of 9-22 μM. Biological tests suggest that the...